The voyage of the “Beagle ” in 1831–6 was not only the starting-point of Charles Darwin's scientific career, but also, and more particularly, it laid the foundation for the whole of his geological work, as embodied in the well-known series of volumes. The collections which, he gathered during that prolonged voyage of exploration have therefore no small interest of a historical and sentimental kind. It is believed that they possess also a certain intrinsic value; inasmuch as an examination of these original specimens, with the advantages conferred by modern petrographical methods, may sometimes help towards a better understanding of the recorded observations. Owing to his choice of plain language in preference to the now antiquated terminology of his time, Darwin is seldom obscure to a modern reader; but his characterization of the ‘igneous rocks which he observed is necessarily crude and vague. Not a few passages may be considerably elucidated by merely indicating the nature of the rocks which are designated by such old-fashioned comprehensive names as ‘porphyry,’ ‘greenstone,’ and ‘basalt.’

The following notes on three fossil plants handed to me by Dr. Hume have been written at the request of Capt. Lyons, Director-General of the Survey Department of Egypt. The material is unfortunately too fragmentary to admit of satisfactory determination; but in view of our ignorance in regard to the former vegetation of Egypt, it is desirable to put on record all available information. Of the three fossils only one is sufficiently well preserved to be referred with any degree of certainty to a genus.

The rocks of the Parys Mountain, which lies about two miles to the south of the town of Amlwch in Anglesey, were described in 1878 by the late Mr. T. Fanning Evans, H.M. Inspector of Mines, who regarded the Parys Mountain “as an outlying piece of ground, geologically identical with the region in which the great slate-mines of Festiniog occur, and from which it differs only in being developed on a much smaller scale, and in being highly metalliferous.”

The following note is based on two papers by Professor A. G. Nathorst and on further details which he has kindly communicated by letter. For the loan of the block (Fig. 1) thanks are due to Dr. H. Munthe, Secretary of Geologiska Föreningen i Stockholm.

By the term ‘collodion imprint’ is meant the impression of any surface on a thin film of collodion. Such an impression is obtained by letting a drop or two of collodion dissolved in ether fall on the surface to be copied. The ether evaporates rapidly, so that in two or three minutes the film is hard. If it does not of its own accord come loose at the corners, it is easily raised by a needle or sharp knife. It is then lifted on to a glass microscope-slide and preserved dry under a cover-slip held in position by gummed strips of paper or by Canada balsam. When the imprint is very sharp, the film can, if desired, be preserved in glycerine-jelly without its distinctness being greatly affected. Some films may be less successful than others, and some may curl too much, so that it is as well to take more than one imprint. In any case it is advisable to throw away the first made, since it usually retains some dust from the surface of the object, whereas following films will be free from this. If the collodion solution is too thick it may be thinned by the addition of ether or of ether and alcohol.

For many years Niagara Falls and the Great Lakes of America have been special subjects of my researches. These at last have been completed under the Commission from Dr. Robert Bell, acting Director of the Geological Survey of Canada, and later of Mr. A. P. Low, Director, with results beyond anticipation. These were obtained through precise instrumental measurements, borings, and soundings, not hitherto undertaken.

My recent survey of the crest-line (1904–5), compared with that of Professor James Hall, 1842, shows the mean rate of recession to have been 4·2 feet a year, with the average breadth of the gorge produced by the falls being 1200 feet. But a longer record (agreeing with the more recent) has been found by Mr. James Wilson and myself in discovering the position of the Falls in 1678, from the crude description and picture made by Father Hennepin at that time. Between 1890 and 1905 the rate of greater recession diminished.

I succeeded in making soundings under the Falls and throughout the Gorge by the use of Tanner-Blish self-registering tubes, depending upon the hydrostatic pressure, as the current was too strong for the use of an ordinary line. At the Whirlpool, and at some other places, it was necessary to work from a cable swung across the Gorge. Under the Falls themselves, the sounding tubes were inserted in a specially designed buoy which the force of the Fall drove down to the rocks, that had collapsed beneath the Falls themselves. These were reached at 72 feet, while the floor of the river beyond varied from 84 to 100 feet below the surface of the river.

Although the succession of Cretaceous beds on Black Ven is well known and much has been written on the various members of the series, only cursory references have been made to those on Stonebarrow Cliff on the east of Charmouth, and the lower beds have never been recorded therefrom. A full list of the literature on the geology of this district, including all that has been written on the Selbornian, is given in the Survey Memoir on the “Geology of Sidmouth and Lyme Regis” and another bibliography in the account of the last excursion to Lyme by the Geologists’ Association.

Mr. Clement Reid's explanation of the broken and contorted condition of the Chalk seems to me quite incomprehensible. Let us analyze the position rather more closely. The champions of ice as the cause of the phenomenon we are discussing appeal to it in two forms—ice-sheets and icebergs. Mr. Eeid was, I believe, the originator of the notion that the dislocations of the Norfolk Chalk were due to an ice-sheet, which means an ice-sheet occupying the North Sea.

On several previous occasions the author has described in the pages of the Geological Magazine certain fossils from so-called “Slade Beds” from the roadside near St. Martin's Cemetery, Haverfordwest. A large collection of fossils has been made by Mr. V. M. Turnbull from this particular locality during the last few years and presented to the Sedgwick Museum. From a prolonged study of this material and comparison with the typical fauna of the Slade Beds as described by Messrs. Marr & Roberts, the conclusion has been forced upon me that we have here to deal with a higher palæontological horizon than the true Upper Bala of this district, and that there is much more reason for putting it in the Silurian than for keeping it in the Ordovician. The stratigraphical evidence which has subsequently become available is in support of this view. A list of the fossils from this bed may be useful at the present moment, particularly as the Sedgwick Museum possesses by far the most extensive series which has been collected from it (see opposite page, 537).

The rock in which they occur is a greenish-grey, fine-grained, argillaceous mudstone with occasionally minute specks of mica and a little arenaceous material, but usually of a very uniform smooth texture. It breaks in an irregular, often subconchoidal manner, and is devoid of any regular or weil-marked planes of division. Exposed surfaces and the fossils themselves are generally more or less iron-stained. In appearance and general characters it is difficult or impossible to distinguish the rock from the higher beds of the Slade Series, but the fauna is completely different.

The general direction of glaciation in the north-east of Anglesey is from about N.N.E. to S.S.W., with local variations of a few degrees on either side. These are but of minor importance, the general trend being remarkably steady, so much so as even to indicate before-hand the existence and approximate position of unknown occurrences of certain rocks by thin trains of boulders.

In August last, at the meeting of the British Association at York, I gave a general account of the zonal succession of the Carboniferous Limestone as developed in Westmoreland and North Lancashire, and I instituted a comparison with beds of a similar age in the Ingleborough and North Pennine districts.

Spheroidal concretions from the Yarra estuary which were to found to contain plant-remains were described by Mr. Chapman recently in this journal. The structures in themselves are of considerable interest to geologists, and also to palæobotanists from the fact that they contain “matted fragments of woody and foliaceous-material.” They were made the subject of some comparisons with the calcareous concretions from the Lancashire Coal-measures, and as a result certain general considerations were brought forward, which call for comment, and which are of sufficient importance to receive attention.

My attention was first drawn to this subject by the study of a remarkable crystal breccia, occurring at Kakanui, New Zealand, of which a description is given below. The only similar phenomena I could read of in the Colonial libraries at my disposal were those of the diamond pipes at Kimberley, described by Professors Carvill-Lewis, T. G. Bonney, and Miss Kaisin in this Magazine.2 Having since had the opportunity, thanks to the hospitality of Professor Lacroix, of studying in his laboratory at Paris, I found that the proper discussion of this subject comes under the study of the inclusions of volcanic rocks, of which he has given so admirable an account in his book “Les Enclaves des Roches volcaniques.”3 At his recommendation I collected some inclusions from the well-known dolerite of Portrush, and studied them under his guidance. The present paper consists of a discussion of rocks from these two localities, with descriptive notes on a few other inclusions that I have in my collection.

Two things stand out clearly from a cursoiy examination of this book, the frequency, almost the universality, of inclusions in igneous rocks, and the importance of the aid which they afford to the student of volcanic phenomena. Under these circumstances, it is remarkable how long this branch of study has escaped attention from. British geologists. Lacroix's useful nomenclature has not been adopted in our literature, although Phillips, Teall, Sollas, Harker, Judd,1 and others have paid considerable attention to some varieties of inclusion, and Harker has established a slightly different classificationof these phenomena.

In connection with the meeting of the Tenth International Geological Congress in the city of Mexico, an excursion, known as the Jorullo Excursion, was organised, of which the following is an account:—

Nevado de Toluca.

It is rarely the ease that we find complete individuals of any species of Lichas, especially in the Ordovician rocks, but several entire specimens belonging to a new British species have been recently collected by Mr. V. II. Turnbull from the Dufton Shales near Melmerby, and detached head shields, pygidia, and hypostomes from the same locality and horizon are not uncommon. Since most species of Lichas have been founded on detached and isolated portions of the body, it is desirable to give a somewhat full description of this new form, which belongs to a group of the genus not previously recognised with certainty in the British Isles.

During the last few months the preparation of a descriptive catalogue of the magnificent collection of reptilian remains obtained by Mr. A. N. Leeds in the Oxford Clay of Peterborough, has rendered it necessary to examine in some detail the fine series of more or less complete skeletons of Ophlhalmosurus preserved in the British Museum. In the course of this examination a certain number of new facts have come to light, and since it will be some time before the detailed description can appear it seems desirable to give a brief account of some of the more interesting points.

As a worker among the Lower Palæozoic rocks of Wales I have for some years devoted a good deal of time to the study of Tremadoc and Arenig rocks, and in common with others have therefore often wished to check the results attained in that district of great thicknesses and tectonic complication by reference to the thinner and more fossiliferous series of the undisturbed areas of Northern Europe. When, therefore, the Senate of the University of Cambridge granted me the Worts Fund for travelling scholars, and instructed me to study the interrelationships of the Tremadoc and Arenig Series in Scandinavia, I at once took advantage of the opportunity, and spent the months of May, June, and July in hammering over those rocks in the field.

One is frequently asked the question, how long ago is it since certain geological phenomena took place in which the questioner is interested for the time being. How long ago were the great coal-beds deposited, or how long ago is it since the chalk was formed at the bottom of the sea?

A Small fossil with a wheel-shaped body borne on a narrow stem has long been known from the base of the Holaster planus zone in the Isle of Wight. It has been recognized as one of the Bryozoa, but has not been described, although once recorded as “near Defrancia diadema, Hag.” It has also been recorded by Dr. A. W. Rowe as “the beautiful little rotiform Bryozoon.”

The following diagnosis has been lying unpublished for eight years in the manuscript of the second volume of the Catalogue of Cretaceous Bryozoa in the British Museum. A preliminary account of the species is now issued, as the name is wanted for reference in the course of Dr. A. W. Rowe's forthcoming memoir on the Chalk of the Isle of Wight. A fuller account of the species with illustrations, on plates drawn in 1900, will be given in the Catalogue, which it is hoped will be issued during this Winter.

Blcavea Rotaformis, n.Sp.

Diagnosis.—Zoarium simple or compound, with a narrow cylindrical stem, attached in a circular concavity in the lower part of the body. The body of the zoarium is discoid, or wheel-shaped, and has on the margin a series of vertical radial projections like cog-wheels. The cogs usually project for a distance nearly equal to the radius of the disc. The cogs may be prolonged at their upper, outer corner into spike-like fasciculi. The upper surface between the bases of the fasciculi is depressed, and occupied by the small, crowded, irregular apertures of the intermediate, subordinate zoœcia.

In venturing to offer some further criticisms on the interpretation of the phenomena presented by Norfolk geology published in the memoirs of the Geological Survey and elsewhere, I may state that these criticisms are the result of several visits to the county in which I have either drawn or made detailed notes of nearly every critical section along the coast.

In a paper read recently at a meeting of the Geological Society, Dr. Washington proposes to treat certain basalts of the Western Mediterranean basin as constituting “a hitherto unrecognised petro-graphic province, or comagmatic region, one of the most salient characters of which is the presence of salfemanes (basalts) that contain remarkably high amounts of titanium.”